114 THE RELATION OF PLANTS TO TIDE-LEVELS 
nove-belgii, Carex tenera, Eleocharis olivacea, Hrechtites hieracifolius, Hypert- 
cum virginicum, H. canadense, H. mutilum, Impatiens biflora, Limonium 
carolinianum (in places), Lysimachia terrestris, Spartina patens (in belts of 
Juncus, Scirpus, or Spartina glabra). 
Some of the above list are not marked on the map at all. Where a series of 
parallel lines represents a species (¢. g., Spartina patens), the lines are drawn 
farther apart where the plant is less plentiful. For symbols not explained on 
plate xxi see Table F, page 153. 
2. DESCRIPTION OF THE STRIP. 
A. THE LIE OF THE LAND. 
The wagon-road on the south of the strip is macadamized, and occupies a 
causeway built about 6 feet above the level of the Marsh. The bank slopes down 
to the Marsh as steeply as the earth and gravel of which it is made would lie, 
that is, about 30°. The foot of the bank is about 9 feet above mean low water. 
Very high winter tides wash much débris as far as this bank. Thus beds of 
dead stems of Spartina glabra and occasional timbers 6 inches in diameter may 
be found anywhere over our area. 
From the foot of the bank to the %-foot contour the Marsh forms a smooth 
plain. The only irregularities are the occasional tide-pools and mud-flats 
marked on the map. The pools are flat-bottomed depressions of 4 to 6 inches 
depth. The margins are usually vertical, but sometimes the bottom of a narrow 
arm of such a pool rises gently to the level of the surrounding sod, forming a 
mud-flat. Other mud-flats of this region are not connected with any depression. 
At about the 7-foot contour, in our area, the ground falls off rapidly, or even 
abruptly. This contour marks the beginning of the dominant and pure growths 
of Spartina glabra. 
B. THE PLANT COVERING IN DETAIL. 
The vegetation of this strip shows several well-marked zones, or belts, which 
may be designated along the east side of the strip as follows: 
i. Wmoadside-graga «Belt: 2.5 eecce Oe ee 516 south to 497 south. 
Dy *ECOTT “BGIL, vote ok ee a ihe a aie oie eee 497 south to 450 south. 
33 RCW DUS OMeTICUNUS Hell... 2.07. seen 450 south to 340 south. 
4. :Jduncas-Snarting’ Belt. 500.23 ore eee 340 south to 93 south. 
5. Spartina patens Belt. aia. aele ae 93 south to 18 north. 
Se Distichiis ( Belt’, e754 a aineereee cae: 18 north to 28 north. 
7. Spartina glabra Muhl. var. alternifiora 
(Lidisel)  Merr. te. cars, Agee ees eee ee 28 north to 70 north. 
1. THE ROADSIDE GRASS BELT OR BELT OF AGRICULTURAL GRASSES. 
This area presents a uniform appearance as of a rather sterile and neglected 
grassy meadow (fig. 1). The grasses are denser and taller on the 2 feet of level 
ground at the edge of the roadbed. This area is at once seeded and fertilized by 
washings of manure from the road. The dominant species is Agrostis alba, 
which grows about 20 inches tall. With it occur: 
pS tay ae } subdominant. 
Dactylis glomerata 
Agropyron repens sparse. 
Panicum sp. 
« All measurements of height of vegetation were made after July 15, 1910. 
